The subject invention generally relates to a fluxing apparatus for applying powdered flux to an object, such as a heat exchanger for a vehicle.
Fluxing apparatuses, or fluxers, are known in the art. A fluxer is utilized in combination with a core stacking machine, a thermal degreasing unit, and a brazing furnace to manufacture an object, such as a heat exchanger for a vehicle.
More specifically, as is known in the art, the fluxer is utilized to apply flux to a surface or surfaces of the heat exchanger. The flux, which is a caustic chemical that dissolves existing metal oxide and prevents the formation of metal oxide, melts just below the temperature at which a layer of braze material, that is previously clad to the surface of the heat exchanger, melts. As such, the flux eliminates metal oxides which are detrimental to the wetting and flow of melted braze material into joint interfaces between the discrete components that make up the heat exchanger.
Generally, there are two types of flux, a wet slurry flux and a powdered flux. Conventional fluxers apply the powdered flux to the heat exchanger in one of two manners. The heat exchanger is either processed through a fluidized bed of the powdered flux, or the powdered flux is spray applied onto the heat exchanger.
The conventional fluxers that spray apply the powdered flux onto the heat exchangers are deficient for a variety of reasons. For instance, these conventional fluxers are prone to repeated failure and extensive service. The powdered flux, which has a fine, yet abrasive, particle size, wears excessively on the working components of the conventional fluxers, such as the gun nozzles and delivery tubes for the powdered flux. Further, these conventional fluxers do not make efficient use of the powdered flux. First, the powdered flux that is overspray, i.e., not adequately applied to the heat exchanger, is frequently allowed to exit the conventional fluxer. As a result, the factory or work area surrounding the conventional fluxers becomes contaminated with the powdered flux, which may create a safety hazard. Also, because the overspray is not recovered and recycled to be re-applied to other heat exchangers, significant amounts of the powdered flux are wasted which increases operating costs. The conventional fluxers are also limited in that they are only equipped to flux certain types of heat exchangers depending on their size. That is, the conventional fluxers are not dynamic because they cannot detect and then accommodate heat exchangers of various sizes.
Due to the deficiencies of the conventional fluxers that apply powdered flux, including those described above, it is desirable to provide a fluxing apparatus that is more reliable with increased wear-resistance and that incorporates a flux recovery system to retain excess powdered flux within the fluxing apparatus. It would also be advantageous to provide a fluxing apparatus that is able to recover and then recycle the excess powdered flux to minimize operating costs, and to provide a fluxing apparatus that is dynamic such that heat exchangers of all shapes and sizes can be fluxed.
A fluxing apparatus is disclosed. The fluxing apparatus applies powdered flux to an object. The fluxing apparatus integrates several components including an enclosure, a conveyor, a supply hopper, at least one application device, and a flux recovery system.
The enclosure defines a fluxing chamber where the object is fluxed. The enclosure includes an inlet and an outlet. The inlet receives the object into the fluxing chamber prior to application of the powdered flux and the outlet discharges the object from the fluxing chamber after the powdered flux has been applied. The conveyor extends through the enclosure between the inlet and the outlet. The conveyor traverses the object into and out of the fluxing chamber.
The supply hopper stores the powdered flux, and the application device, which is in fluid communication with the supply hopper and which is positioned to face at least one side of the conveyor, applies the powdered flux to the object.
The flux recovery system is in fluid communication with the fluxing chamber. The flux recovery system introduces and maintains a negative pressure within the fluxing chamber. As such, excess powdered flux is retained within the enclosure. Furthermore, the excess powdered flux can be recovered and then recycled to the supply hopper.
Accordingly, the subject invention provides a fluxing apparatus that integrates the components described above to achieve synergistic benefits. The fluxing apparatus of the subject invention integrates components that have increased wear-resistance and, therefore, last longer in service. This fluxing apparatus also incorporates a flux recovery system that minimizes operating costs by retaining excess powdered flux within the apparatus and then recovering and recycling this flux. In other word, the fluxing apparatus of the subject invention utilizes less flux overall. Additionally, it is advantageous that the fluxing apparatus of the subject invention can detect varying shapes and sizes of heat exchangers and can then adjust to accommodate such different heat exchangers.